Remove and fix useless drop of reference

Author: Urgau

std/src/sys/sgx/waitqueue/mod.rs

@@ -207,7 +207,7 @@ impl WaitQueue {
                 let mut entry_guard = entry.lock();
                 let tcs = entry_guard.tcs;
                 entry_guard.wake = true;
-                drop(entry);
+                drop(entry_guard);
                 Ok(WaitGuard { mutex_guard: Some(guard), notified_tcs: NotifiedTcs::Single(tcs) })
             } else {
                 Err(guard)

std/src/sys/unix/fs.rs

@@ -1210,7 +1210,7 @@ impl File {
                 // Redox doesn't appear to support `UTIME_OMIT`.
                 // ESP-IDF and HorizonOS do not support `futimens` at all and the behavior for those OS is therefore
                 // the same as for Redox.
-                drop(times);
+                let _ = times;
                 Err(io::const_io_error!(
                     io::ErrorKind::Unsupported,
                     "setting file times not supported",

std/src/thread/tests.rs

@@ -375,7 +375,9 @@ fn test_scoped_threads_nll() {
     // this is mostly a *compilation test* for this exact function:
     fn foo(x: &u8) {
         thread::scope(|s| {
-            s.spawn(|| drop(x));
+            s.spawn(|| match x {
+                _ => (),
+            });
         });
     }
     // let's also run it for good measure